The technology of the present disclosure relates to an image forming apparatus.
In an electrophotographic image forming apparatus, there are some cases where a heater is disposed in the image forming apparatus in order to prevent dew condensation of a photosensitive drum or an exposing device. The heater is provided to machine parts, such as the photosensitive drum and an optical device, in which dew condensation easily occurs.
A power supply circuit of the image forming apparatus is connected to either a load system circuit, which supplies power to an image forming apparatus body, or a heat system circuit, which supplies power to the heater, via a changeover switch. The changeover switch can be switched interlocking with a power switch of the image forming apparatus. The changeover switch connects the power supply circuit to a main circuit when the power switch is in an ON state, and connects the power supply circuit to the heat system circuit when the switch is in an OFF state. The power supply circuit is provided with a timer. The timer operates the heater by closing a contact point provided to the heat system circuit when a preset time has come.